"What's the difference between Scientific Linux 6.x and Enterprise or CentOS 6.x?How much was changed? Am I allowed to use Scientific Linux? How does development work here?"

These are just some questions that get asked very often.

Here I provide a quick breakdown that hopefully will answer these questions, and any misconceptions you may be having about SL 6.x

1. Goals

CentOS:

QUOTE

CentOS is an Enterprise-class Linux Distribution derived from sources freely provided to the public by a prominent North American Enterprise Linux vendor. CentOS conforms fully with the upstream vendors redistribution policy and aims to be 100% binary compatible.

Scientific Linux:

QUOTE

One of the goals of Scientific Linux is to be as close to the original vendor release of Enterprise Linux. But there are several things that people want to change, for one reason or another. In order to have both worlds we have created these tweak rpm's, more commonly known as SL rpm's. These rpm's can be added or removed to add or remove a feature. It is up the individual user to determine if they want a particular feature or not.

In short: CentOS, in general, will try to not make *any* tweaks to their system that are not in upstream. Scientific Linux on the other hand has a similar goal of trying to be as close to upstream as possible, but they added/changed a few small things.

Many of the changes are very minor. A lot of the added packages such as openafs, revisor, and icewm are not installed by default. Little things like "httpd" - changed index.html file and release name are basically nothing. The only thing you may want to watch out for is the yum-autoupdate. Some people prefer it, others don't. Remove it if you don't want yum auto-updating your system.

As you can see, Scientific Linux 6.x is very much an Enterprise clone at its core. Contrary to some beliefs, it is not "loaded with science programs" or hacked up with so many changes specific for labs at CERN and Fermi.

We can call it "99% like Enterprise."

3. Other changes

With Scientific Linux 6, you get the choice of staying with your current point release. This means that if you are using 6.0, you don't have to upgrade right away to 6.1 to keep getting security updates and bug fixes. SL's team does testing on packages and back ports them if they can to older releases. SL also separates bugfixes and security patches into separate repositories - for whatever reason, you may choose what you want to have. This is not supported on CentOS or Enterprise.

4. History

Scientific Linux has been around since 2004. The primary reason it was developed was for use in labs and universities everywhere to be able to download it and either use it as a free alternative to Enterprise, or they could modify the system and shape it to their needs. This is why the end product of Scientific Linux isn't full of "Science applications" or is heavily modified to begin with. It is mostly a plain end-product and they leave it up to whoever needs it to decide what they want to do.

Of course this means that at any time Fermilab and CERN could stop funding the project. However, the project has been around for a number of years now, and there are obvious technical AND financial benefits of funding these projects. Overall, the foundation of the project is strong.

Since it is a paid team of developers, regular community users cannot join the project. However, the flip side of this is that the development process is quite open.

SL releases Alpha and Beta versions of their releases before the final version is out. These releases are open to the public and you are allowed to give feedback on anything you find. You can keep track of everything of course on the mailing lists.

7. Requirements for use

There are NO requirements to use or modify Scientific Linux to fit your needs. You do not need to be a research lab or a university. Anyone can download the distro and install it on any system they choose, any time. The more users that use Scientific Linux; the better the distro can get.

8. Official Support

There is only 1 official support channel - that's at the SL mailing list. The link to the mailing lists is here:

Since Oracle has gone "public", that probably should be mentioned here now. I have it on a machine for testing. I'm missing the small changes SL has made that are convenient in Software Manager, so far, but other than that.....UEK kernel is "newer" which doesn't mean much.